Sprint car wings are one of the defining features of the race cars. The wings, more specifically known as the top wing, are generally five foot by five foot, and are mounted above the head of the driver of the car. The wings provide downforce and safety for the cars. Furthermore, sprint cars may include smaller front wings or nose wings to help balance the race car and to keep the front of the car planted to the track.
The top wings act like upside down aircraft wings, creating downforce instead of lift. A wing generates downforce due to the air pressure differential between the top and bottom surfaces of the wing. Due to the shape and angle of attack of the wing, the air below the wing travels faster than that above, meaning that the air pressure on the underside of the wing will be lower. The speed of the air above the wing is either not changed or slowed by the shape of the wing, meaning the pressure of the air above the wing is higher than the air flowing under the wing. The downforce is created as the high pressure area on top of the wing is drawn to the low pressure area under the wing forcing the wing down. As the speed of the wing moving through the air is increased, so is the downforce. The horizontal portion of the top wing, also known as the wing belly, is also generally angled to most efficiently create the downforce. Therefore, an angle of around 20-30° may provide the best downforce.
Top wings also include left and right side boards, which are also known as tip plates. The side boards have multiple advantages. The boards ensure that the high air pressure area moving over the top surface of the wing is not allowed to spill over the sides and into the low pressure area under the wing and vice versa. If the pressures were allowed to mix, a whirling vortex would be produced, which affects the efficiency of the wing by reducing downforce, increasing drag and in some circumstances causing lift. Another important job performed by the tip plates is to create what is known as sideforce. This is the force that acts towards the inside of the race track. To create sideforce the left tip plate is positioned higher above the wing than the right tip plate, this is to allow the high pressure air on top of the wing to push more on the left side of the wing. The right tip plate is positioned lower below the wing than the left tip plate, causing the low pressure area pull to increase on the right tip plate.
Typically, the side boards are single-layered boards that include a kicker or turn out at the rear section. The turn outs aid in the turning and the downforce of the wings. The side boards are attached to the wing belly at approximately 90° by the use of angled struts between the interior side of the boards and the wing belly. These struts can create turbulence, drag, and bad air flow around the wing. Furthermore, the wing belly has been a uniform shape and thickness on both the right and left sides of the belly. To change the amount of downforce and the location of the same, the belly would have to be tilted by wing mount, which could affect the airflow around other portions of the wing.
There are also various rules and regulations that the wings must comply with. The rules designate the width of the belly, width of the side boards, length of the kickers, angle of the connections, etc. The rules are in place to try to increase the safety of the races, while also keeping the cars in a somewhat even playing field.
Therefore, there is a need in the art for a top wing assembly for a sprint car type racing car that increases the speed and safety of the cars, while also complying with the rules and regulations of the races and racing series.